JP4706609B2 - Piezoelectric vibration device - Google Patents

Description

  The present invention relates to a piezoelectric vibration device such as a crystal resonator used in an electronic apparatus.

  Piezoelectric vibration devices such as surface-mount type crystal resonators that are currently widely used use a ceramic package having a region for accommodating the crystal vibration element. After mounting the crystal vibration element on the ceramic package, the lid is hermetically sealed with a lid. Many configurations are adopted. For example, Japanese Patent Laid-Open No. 2000-236035 (Patent Document 1) is a prior art showing an example.

  In the configuration using such a ceramic package, when the piezoelectric vibration device is further reduced in size, there is a possibility that the ceramic package cannot cope with the reduction in size. For example, a ceramic body constituted by using a ceramic lamination technique by firing always varies in dimensional accuracy. When the ceramic body is miniaturized, it becomes difficult to ensure desired dimensional accuracy due to the variation. In addition, when a reduction in height is required, sufficient package strength may not be ensured by ceramic lamination. In such a case, environmental resistance performance such as airtightness required as an electronic component may not be satisfied.

  Furthermore, in order to mount the crystal resonator element on the package, a mounting device and a jig are required. However, there is a problem that it becomes difficult to mount the crystal unit due to the jig interfering with the package. It was.

  If the piezoelectric vibration device is further miniaturized in this way, it may not be possible to cope with the configuration using a ceramic package that is currently popular, and a piezoelectric vibration device configuration suitable for ultra miniaturization has been demanded. .

JP 2000-236035 A

  The present invention has been made in view of the above points, and provides a novel chip-type piezoelectric vibration device that can reliably hold and hermetically seal a piezoelectric vibration element even when it is miniaturized. With the goal.

  In order to achieve the above object, the present inventor aims at a configuration in which the piezoelectric vibrating plate can be easily held and the package can be easily formed even when the piezoelectric vibrating device is miniaturized. A block-shaped terminal body is provided on the main surface, and the two terminal bodies are mounted so as to be in direct contact with the mounting board. This is realized by such a configuration.

  That is, it comprises a piezoelectric diaphragm, an excitation electrode for supplying excitation energy to the piezoelectric diaphragm, and each terminal body connected to the vicinity of the front and back outer periphery of the piezoelectric diaphragm, and each terminal body is the excitation electrode. The piezoelectric vibration device is characterized in that each terminal body is in direct contact with the mounting substrate and is electrically and mechanically connected by a conductive bonding material.

As a more specific configuration, as shown in claim 1, a rectangular piezoelectric diaphragm in which a pair of excitation electrodes is formed on the front and back main surfaces and an extraction electrode connected to the excitation electrode is drawn out in the vicinity of the outer periphery; A piezoelectric vibration device having a pair of rectangular parallelepiped block-like terminal bodies connected to the front and back outer periphery of the piezoelectric diaphragm and having a joint surface that is the same as or larger than the front and back main surfaces, each terminal body being one of the lead electrodes Or, it has a wiring pattern connected to only the other, and the electrode is led out on the opposite surface of the bonding surface connected to the piezoelectric diaphragm, and each terminal body is in direct contact with the mounting substrate and electrically connected with the conductive bonding material. Mechanically connected, the terminal body is composed of a reinforcing portion and a terminal portion, the reinforcing portion is connected to the vicinity of the front and back outer periphery of the piezoelectric diaphragm, and the excitation electrode is externally connected by the terminal portion connected to the reinforcing portion. Derived It is characterized in Rukoto.

  For example, when the piezoelectric diaphragm is an AT-cut quartz diaphragm, the frequency is determined by the thickness thereof. However, when the piezoelectric diaphragm is a high frequency, the thickness is about several tens of μm. Excitation electrodes and extraction electrodes are formed on the front and back main surfaces of the piezoelectric diaphragm. By connecting the terminal body to the front and back main surfaces of such a piezoelectric diaphragm, the piezoelectric vibration device can be configured in a chip shape, and such a terminal body is mounted on the mounting substrate so as to be in direct contact with the mounting substrate. Thus, the piezoelectric diaphragm is installed on the mounting substrate in a standing state. The terminal body is made of, for example, a rectangular parallelepiped block-like insulator, and a necessary wiring pattern is formed on the surface or inside of the insulator. For example, an electrode connected to an extraction electrode connected to the excitation electrode of the piezoelectric diaphragm is formed on a surface facing the piezoelectric diaphragm, and the electrode is connected to the wiring pattern through a part of the wiring pattern formed on the terminal body. An electrode is drawn out on the opposite surface of the bonding surface or in the vicinity of the opposite surface. With such a configuration, a connection electrode can be formed at both ends of the chip component.

  According to each of the above configurations, each excitation electrode formed on the front and back surfaces of the piezoelectric diaphragm can be directly conductively joined to the terminal body connected to the front and back main surfaces of the piezoelectric diaphragm, so that no complicated wiring is required. In addition, by pulling out the electrodes to the terminal body and each terminal body being directly bonded to the mounting substrate, a chip-like piezoelectric vibration device can be obtained with an extremely simple structure. In particular, by adopting a rectangular parallelepiped block configuration for the terminal body, stable mounting can be performed on the mounting substrate. Therefore, the problems associated with the downsizing of the package and the mounting of the piezoelectric diaphragm on the package that have occurred in the past do not occur.

Moreover, a buffer function improves by making a terminal body into multiple member structure. For example, when a piezoelectric vibration device is mounted on a mounting board, stress from the mounting board side may propagate to the piezoelectric diaphragm, but this stress propagation will be mitigated by the multiple member configuration of the terminal body, This leads to stable characteristics of the piezoelectric vibration device.

According to a second aspect of the present invention, a pair of rectangular parallelepiped block diaphragm-shaped terminal bodies connected to the vicinity of the front and back outer peripheries of the piezoelectric diaphragm, and having a joint surface that is the same as or larger than the front and back main surfaces, Each of the terminal bodies has an excitation electrode on a surface facing the piezoelectric diaphragm, and an extraction electrode that draws the excitation electrode to the vicinity of the outer periphery of each terminal body. In addition, each terminal body is in direct contact with the mounting substrate and is electrically and mechanically connected by a conductive bonding material. The terminal body includes a reinforcing portion and a terminal portion, and the reinforcing portion is near the front and back outer circumferences of the piezoelectric diaphragm. The excitation electrode may be led out to the outside by a terminal portion connected to the reinforcing portion.

  According to each said structure, the said terminal body is a structure which has an excitation electrode in the surface facing the said piezoelectric diaphragm, and becomes a structure which applies an excitation voltage with respect to a piezoelectric diaphragm by what is called an air gap system. Since such an excitation electrode has a lead-out electrode that leads to the vicinity of the outer periphery of each terminal body, the electrode is pulled out from the terminal body without requiring complicated wiring, and each terminal body is directly bonded to the mounting substrate. With this configuration, a chip-like piezoelectric vibration device can be obtained with a very simple configuration. In particular, by adopting a rectangular parallelepiped block configuration for the terminal body, stable mounting can be performed on the mounting substrate. Therefore, the problems associated with the downsizing of the package and the mounting of the piezoelectric diaphragm on the package that have occurred in the past do not occur.

Moreover, a buffer function improves by making a terminal body into multiple member structure. For example, when a piezoelectric vibration device is mounted on a mounting board, stress from the mounting board side may propagate to the piezoelectric diaphragm, but this stress propagation will be mitigated by the multiple member configuration of the terminal body, This leads to stable characteristics of the piezoelectric vibration device.

According to a third aspect of the present invention, the terminal body may be connected to the vicinity of the front and back outer peripheries of the piezoelectric diaphragm, and a cavity may be formed at a position facing the central portion of the piezoelectric diaphragm.

The cavity is for securing a vibration region (vibration space) of the piezoelectric diaphragm, and is formed by providing a recess in the piezoelectric diaphragm or the terminal body, or a bonding material for joining the piezoelectric diaphragm and the terminal body. Can be obtained by increasing the thickness. The structure of the cavity is such that a vibration space is provided so that the excitation electrode formed on the piezoelectric diaphragm is at least a vibration region, but the vibration region is substantially determined by the shape of the excitation electrode. What is necessary is just to examine a structure. According to this configuration, since the vibration space can be reliably ensured, the characteristics as the piezoelectric vibration device can be improved.

Further, as shown in claim 4, the piezoelectric diaphragm has a configuration in which the vicinity of the outer periphery connected to the terminal body has a thick portion, and the central portion has a thin portion thinner than the thick portion. A so-called reverse mesa configuration in which an excitation electrode is formed or an excitation electrode is formed in a region corresponding to the thin portion of the terminal body or the reinforcing portion may be employed.

In the above configuration, the piezoelectric vibration device has an extremely high frequency by making the vicinity of the outer periphery of the piezoelectric diaphragm a thick part, connecting the thick part to the terminal body, and separating the thin part at the center from the vibration region. And the mechanical strength of the piezoelectric diaphragm can be improved.

According to this configuration, the vibration space is formed by the thin portion without adopting the above-described configuration in which the cavity is provided on the terminal plate side, but depending on the thickness of the thin portion, the thickness of the excitation electrode, etc. Even in the configuration having the thin portion, a cavity may be provided on the terminal plate side.

Further, in the configuration having the thin portion, as shown in claim 5, the thin portion extends obliquely from one main surface or the main surface of the thick portion to the other main surface or the main surface of the thick portion. An arrangement configuration may be used. Such an oblique arrangement configuration can be obtained by, for example, using a photolithography technique, a method of intermittently varying the thickness of the resist film, or a method of varying the etching rate.

The oblique arrangement configuration does not necessarily extend from the upper surface of the thick portion surface to the upper surface of the thick portion rear surface, and may be a gentle oblique arrangement configuration from the vicinity of the front surface to the vicinity of the rear surface.

According to this configuration, the region of the thin portion is widened by the oblique arrangement configuration, and the characteristics of the piezoelectric vibration device can be improved by substantially expanding the vibration region.

In addition, as described in claim 6, the above-described buffer function is more effective when the piezoelectric diaphragm and the terminal body or the reinforcing portion and the terminal portion are joined by a flexible resin bonding material. Can do.

With a configuration in which at least one of the piezoelectric diaphragm and the terminal body or the reinforcing portion and the terminal portion is joined by a flexible resin bonding material, stress from the mounting substrate side is relieved, leading to stable characteristics as a piezoelectric vibrating device.

According to a seventh aspect of the present invention, the reinforcing portion may be made of an insulator having a wiring pattern, and the terminal portion may be a metal plate or a metal film formed on the surface of the insulating plate.

Further, in each of the above configurations, the height dimension of each terminal body is larger than the height dimension of the piezoelectric diaphragm, and a gap is formed between the piezoelectric diaphragm and the mounting board when the mounting board is mounted. It may be a configuration.

  With such a configuration, the piezoelectric diaphragm portion can be configured not to be in close contact with the mounting substrate. Therefore, the stress on the mounting substrate side is not directly transmitted to the piezoelectric vibration plate, and the characteristics of the piezoelectric vibration device can be stabilized. Moreover, the short circuit between terminal bodies can also be prevented.

  As described above, according to the present invention, it is possible to obtain a chip-type piezoelectric vibration device that can securely hold and hermetically seal the piezoelectric vibration element even when it is miniaturized. Further, the buffer function of the piezoelectric vibration device is improved, and the characteristics can be stabilized.

  Hereinafter, a first embodiment according to the present invention will be described with reference to the drawings. In the present embodiment, an AT-cut quartz crystal diaphragm that operates by thickness shear vibration will be described as an example of a piezoelectric diaphragm.

  FIG. 1 is an exploded perspective view of the piezoelectric vibration device according to the first embodiment, and FIG. 2 is a cross-sectional view taken along line AA in a state where FIG. 1 is assembled.

  The quartz crystal plate 11 is composed of a flat AT-cut quartz crystal resonator element, and has a rectangular shape in plan view in which the X axis has a long side and the Z axis has a short side on the main surface. In addition, excitation electrodes 111 and 112 are respectively formed in the central regions of the front and back main surfaces of the crystal diaphragm 1. Each excitation electrode has a rectangular shape, and is formed so as to face each other with a crystal diaphragm. In addition, extraction electrodes 111a and 121a connected to the respective excitation electrodes are formed. The extraction electrodes 111 a and 112 a have a narrow width configuration and extend to the vicinity of the outer periphery of the main surface of the crystal diaphragm 1. The excitation electrode may have a rectangular shape with a characteristic adjustment notch, a circular shape, or an oval shape.

  In addition, circumferential metal films 111b and 112b are formed in the vicinity of the outer circumferences of both main surfaces of the crystal diaphragm. The circumferential metal film is used at the time of joining with a terminal body described later. The circumferential metal film is electrically connected to the extraction electrode.

  The excitation electrode, the extraction electrode, and the circumferential metal film have a multilayer thin film electrode configuration, and are formed in the order of, for example, a chromium layer, a gold layer, or a silver layer in contact with a quartz crystal vibration plate. These electrodes may be formed using a vapor deposition mask having openings for forming electrodes, or may be formed using a photolithography technique.

  Terminal bodies 12 and 13 are connected to the front and back main surfaces of the crystal diaphragm 11. The terminal bodies 12 and 13 have a rectangular parallelepiped block shape and are made of an insulator such as crystal or ceramics. Moreover, the terminal bodies 12 and 13 have the joint surfaces 121 and 131 with the quartz-crystal diaphragm 11, and have the formation surface of the connection electrodes 12b and 13b on the opposite surface of the joint surface. A cavity C is provided on the joint surfaces 121 and 131 of the terminal body. The cavity C is a central portion of the joint surface of the terminal body, and is a concave portion corresponding to the excitation electrode forming portion of the crystal diaphragm and having a size larger than that of the excitation electrode. The cavity C may not be formed. For example, by adjusting the thickness of a bonding material (metal brazing material, etc.) for bonding the crystal diaphragm and the terminal body, the cavity C and the terminal body may be adjusted. A vibration space may be formed.

  Further, second circumferential metal films 121a and 131a are formed on the outer peripheral portions of the bonding surfaces 121 and 131 other than the cavities. Further, grooves are formed on the side surfaces of the terminal bodies 12 and 13, and lead-out electrodes 12a and 13a are formed in the grooves. The second circumferential electrodes 121a and 131a and the connection electrodes 12b and 13b are electrically connected by the lead-out electrodes 12a and 13a.

The second circumferential metal film, the lead-out electrode, and the connection electrode have a multilayer thin film electrode configuration, and are formed in the order of a chromium layer, a gold layer, or a silver layer, for example, in contact with the terminal body. A metal brazing material S1 is formed on the second circumferential metal film. The metal brazing material is, for example, a gold tin brazing material, and is formed on the second circumferential metal film using a thick film printing technique or the like.

The crystal diaphragm 11 and the terminal bodies 12 and 13 are joined using the metal brazing material. Specifically, the metal brazing material portion of the terminal body is superposed on the circumferential metal film of the crystal diaphragm in a predetermined atmosphere such as an inert gas, and the brazing is performed by heating at a predetermined temperature condition. Do. By such bonding, it is possible to obtain a chip-type piezoelectric vibration device including a quartz crystal plate whose excitation region is hermetically sealed and a terminal body.

  The hermetic sealing may be performed in a vacuum atmosphere. Alternatively, one main surface of the crystal diaphragm may be vacuum sealed with a terminal body, and the other main surface may be sealed with another terminal body in an inert gas atmosphere such as nitrogen gas. More specifically, frequency variation is achieved by vacuum-sealing one main surface, then adjusting the frequency of the electrode on the other main surface, and then inert gas-sealing the other main surface. Thus, a piezoelectric vibration device with suppressed can be obtained.

Such a piezoelectric vibration device is mounted so that the connection electrodes 12b and 13b are in direct contact with the electrode pads P1 and P2 formed on the mounting substrate P, respectively, and are joined by a low melting point metal brazing material such as lead-free solder. . With such a mounting configuration, each excitation electrode of the crystal diaphragm is electrically connected to each electrode pad.

In the above-described embodiment, the quartz diaphragm (piezoelectric diaphragm) and the terminal body are joined using a metal brazing material, and brazing is performed by overall heating. However, the joining is performed using an energy beam such as a laser beam. The part may be heated locally.

Further, instead of the metal brazing material, a conductive resin bonding material (a resin bonding material containing a conductor) may be used. Since resin bonding materials tend to have better bonding properties with quartz or ceramic substrates, when resin bonding materials are used, the peripheral metal film formed on the crystal diaphragm or the second periphery formed on the terminal body are used. The metal film may not be formed. In addition, as a resin material, a silicone type resin and an epoxy-type resin can be illustrated, for example.

  Further, although an AT-cut quartz plate is used as the quartz plate, for example, a quartz plate having a short side on the X axis and a long side on the Z axis may be used, or a tuning fork type quartz plate with a frame. But you can. As is well known, the tuning-fork type quartz diaphragm needs to be formed with electrodes so that the vibrating arms can bend and vibrate, but it is preferable to finally draw out electrodes of the respective electrodes on the front and back surfaces. And it joins with a terminal body with a frame. In addition, another piezoelectric diaphragm may be used instead of the quartz diaphragm, or may be applied to a piezoelectric vibration device such as SAW (surface acoustic wave).

  Further, the circumferential metal films 111b and 112b formed near the outer periphery of the front and back main surfaces of the quartz diaphragm and the second circumferential metal film formed on the terminal body are located on the inner side of the main surface end portion (ridge portion with the side surface). You may form in. With such a configuration, it is possible to suppress the metal brazing material from protruding to the side surface at the time of bonding, and to suppress a short circuit accident due to the bonding material.

  With the above configuration, it is possible to make a simple configuration without using a ceramic package as in the past, and when the crystal diaphragm is mounted, the configuration is mounted almost perpendicular to the mounting substrate. An extremely small chip-type piezoelectric vibration device can be obtained by the integrated configuration. In addition, by mounting the piezoelectric vibration device on the mounting substrate, the crystal vibration plate is installed perpendicular to the mounting substrate. With such a configuration, there is an effect of suppressing the frequency fluctuation amount of the piezoelectric vibration device against a drop impact or the like.

A second embodiment according to the present invention will be described with reference to FIGS. Also in the second embodiment, an AT-cut crystal diaphragm is used as the piezoelectric diaphragm. 3 is a perspective view of the piezoelectric vibration device, and FIG. 4 is a cross-sectional view taken along the line BB of FIG.

  The second embodiment is mainly different in that the terminal body 12 includes a reinforcing portion 14 and a terminal portion 16, and the terminal body 13 includes a reinforcing portion 15 and a terminal portion 17.

  The quartz diaphragm 11 is composed of a flat AT-cut quartz vibrator and has a rectangular shape in plan view with the X axis as the short side and the Z axis as the long side. In addition, excitation electrodes 111 and 112 are formed in the center regions of the front and back surfaces of the quartz crystal plate 1, respectively. Each excitation electrode has a rectangular shape or a circular shape, and is formed so as to face each other with a crystal vibrating plate interposed therebetween. In addition, extraction electrodes 111a and 121a connected to the respective excitation electrodes are formed. The extraction electrodes 111 a and 112 a have a narrow width configuration and extend to the vicinity of the outer periphery of the main surface of the crystal diaphragm 1.

In addition, circumferential grooves 11a and 11b are formed in the outer peripheral portion of the excitation electrode formed on the front and back surfaces of the quartz crystal diaphragm. By this groove, stress at the time of joining with a terminal body described later and stress from the mounting substrate can be relaxed, and the characteristics of the piezoelectric vibration device can be stabilized.

  Further, circumferential metal films 111b and 112b are formed in the vicinity of the outer periphery of the quartz crystal diaphragm. The circumferential metal film is used at the time of joining with a reinforcing portion described later. The circumferential metal film is electrically connected to the extraction electrode.

  The excitation electrode, the extraction electrode, and the circumferential metal film have a multilayer thin film electrode configuration, and are formed in the order of, for example, a chromium layer, a gold layer, or a silver layer in contact with a quartz crystal vibration plate. Each layer may be formed in the order of chromium, silver, and gold. These electrodes may be formed using a vapor deposition mask having openings for forming electrodes, or may be formed using a photolithography technique.

  Terminal bodies 12 and 13 are connected to the front and back main surfaces of the crystal diaphragm 11. In the present embodiment, the terminal bodies are composed of reinforcing portions 14 and 15 and terminal portions 16 and 17, respectively, and the terminal bodies 12 and 13 as a whole have a rectangular parallelepiped block shape.

The reinforcement parts 14 and 15 are comprised with insulators, such as quartz or ceramics. Further, the reinforcing portions 14 and 15 have joint surfaces 141 and 151 with the crystal vibrating plate 11 and surfaces on which connection electrodes 14b and 15b are formed on the opposite surfaces of the joint surfaces. A cavity C is provided on the joint surfaces 141 and 151 of the reinforcing portion. The cavity C is a central portion of the joint surface of the terminal body, and is a concave portion corresponding to the excitation electrode forming portion of the crystal diaphragm and having a size larger than that of the excitation electrode.

  Second circumferential metal films 141a and 151a are formed on the outer peripheral portion of the bonding surfaces 141 and 151 other than the cavity. Further, grooves are formed on the side surfaces of the reinforcing portions 14 and 15, and lead-out electrodes 14a and 15a are formed in the grooves. The second circumferential metal films 141a and 151a and the connection electrodes 14b and 15b are electrically connected by the lead-out electrodes 14a and 15a.

The second circumferential metal film, the lead-out electrode, and the connection electrode have a multilayer thin film electrode configuration, and are formed in the order of a chromium layer, a gold layer, or a silver layer, for example, in contact with the terminal body. Alternatively, each layer may be formed in the order of chromium, silver, and gold. A metal brazing material S1 is formed on the second circumferential metal film. The metal brazing material is, for example, a gold tin brazing material, and is formed on the second circumferential metal film using a thick film printing technique or the like.

Terminal portions 16 and 17 are joined to the outer sides of the reinforcing portions 14 and 15 by a metal brazing material S2. For example, the terminal portion may be made of a metal body such as copper or Western night, and may have a structure in which a metal plating layer or a metal brazing material is formed on the surface in order to improve connectivity. Further, the terminal portion has an outer dimension that is the same as or slightly larger than the height of the reinforcing portion. Moreover, the terminal part also has the role of a connection electrode by the structure which consists of a metal body.

When assembling the piezoelectric vibrating device, first, the crystal vibrating plate 11 and the reinforcing portions 14 and 15 are joined. That is, the brazing is performed by superimposing the metal brazing material S1 of the reinforcing portion on the circumferential metal film of the crystal diaphragm and heating it at a predetermined temperature condition. In order to obtain an atmosphere when the quartz diaphragm is excited during brazing, airtight sealing is performed by brazing in a vacuum atmosphere when using a vacuum atmosphere, and inert gas such as nitrogen gas is used when creating an inert gas atmosphere. Performs hermetic sealing by brazing in a gas atmosphere. By such bonding, it is possible to obtain a chip-type module in which the crystal diaphragm and the reinforcing portion are integrated and the excitation portion of the crystal diaphragm is hermetically sealed.

Next, a terminal portion is joined to the outside of the chip type module. Although the metal brazing material S2 is used for joining the terminal portions 16 and 17, a conductive resin joining material or a sealing glass material may be used. The metal brazing material S2 is preferably a material having a melting point lower than that of the metal brazing material. Thus, a chip-type piezoelectric vibration device can be obtained. It is also possible to use a method in which the reinforcing portion 14 and the terminal portion 16 and the reinforcing portion 15 and the terminal portion 17 are joined in advance, and then the reinforcing portion side is joined to the crystal diaphragm.

Such a piezoelectric vibration device is mounted so that the terminal portions 16 and 17 are in direct contact with the electrode pads P1 and P2 formed on the mounting substrate P, respectively, and are joined by a low melting point metal brazing material or the like. With such a mounting configuration, each excitation electrode of the crystal diaphragm is electrically connected to each electrode pad.

According to the present embodiment, since the terminal body is composed of the reinforcing portion and the terminal portion, the stress that may be received from the mounting substrate by the connection configuration of the reinforcing portion and the terminal portion can be relaxed, Makes the crystal diaphragm less susceptible to stress. Further, the buffering performance can be further improved by bonding the reinforcing portion and the terminal portion with a highly flexible bonding material, or by using a metal body having a high buffering property such as copper for the terminal portion. it can.

A third embodiment according to the present invention will be described with reference to FIGS. FIG. 5 is a perspective view of the piezoelectric vibration device according to the third embodiment, and FIG. 6 is a cross-sectional view taken along the line CC in FIG.

  In the third embodiment, the size of the reinforcing portion and the terminal portion is different from the first and second embodiments in that the configuration of the crystal diaphragm is an inverted mesa and the configuration of the terminal body. This is the main difference.

The quartz crystal plate 21 is made of an AT cut quartz crystal vibrating element, and the main surface has a square shape in plan view consisting of an X axis and a Z axis. In addition, square-shaped thin portions are formed in the central regions of the front and back main surfaces of the crystal diaphragm 21, and thick portions thicker than the thin portions are formed on the outer periphery thereof, thereby forming an inverted mesa structure. . Excitation electrodes 211 and 212 are respectively formed in the central portions of the thin portions on the front and back sides. Each excitation electrode has a rectangular shape or a circular shape, and is formed so as to face each other with a crystal vibrating plate interposed therebetween. In addition, lead electrodes 211a and 212a connected to the respective excitation electrodes are formed. The extraction electrodes 211 a and 212 a have a narrow width configuration, are each extracted from the thin portion to the thick portion, and extend to the vicinity of the outer periphery of the main surface of the crystal diaphragm 21.

  Further, circumferential metal films 211b and 212b are formed in the vicinity of the outer periphery of the crystal diaphragm. The circumferential metal film is used at the time of joining with a reinforcing portion described later. The circumferential metal film is electrically connected to the extraction electrodes 211a and 212a.

  The excitation electrode, the extraction electrode, and the circumferential metal film have a multilayer thin film electrode configuration, and are formed in the order of, for example, a chromium layer, a gold layer, or a silver layer in contact with a quartz crystal vibration plate. These electrodes may be formed using a vapor deposition mask having openings for forming electrodes, or may be formed using a photolithography technique.

  A terminal body is connected to the front and back main surfaces of the crystal diaphragm 21. In the present embodiment, the terminal body includes reinforcing portions 22 and 23 and terminal portions 24 and 25, respectively. In the present embodiment, the size of the terminal portion is formed larger than the external size of the crystal diaphragm and the reinforcing portion.

The reinforcing portions 22 and 23 are made of an insulator such as quartz or ceramics. Further, the reinforcing portions 22 and 23 have joint surfaces 221 and 231 with the crystal diaphragm 21, and surfaces on which connection electrodes 22b and 23b are formed on the opposite surface of the joint surface. The joint surfaces 221 and 231 of the reinforcing portion have a planar configuration, but a cavity C is formed in the central portion by the thin portion of the quartz crystal plate facing each other.

  Also, second circumferential metal films 221a and 231a are formed in the vicinity of the outer periphery of the front and back main surfaces of the bonding surfaces 221 and 231. Lead electrodes 22a and 23a are formed on the side surfaces of the reinforcing portions 22 and 23, respectively. The second circumferential metal films 221a and 231a and the connection electrodes 22b and 23b are electrically connected by the lead-out electrodes 22a and 23a.

The second circumferential metal film, the lead-out electrode, and the connection electrode have a multilayer thin film electrode configuration, and are formed in the order of a chromium layer, a gold layer, or a silver layer, for example, in contact with the terminal body. A metal brazing material is formed on the second circumferential metal film. The metal brazing material is a low melting point metal brazing material such as gold tin brazing material or gold germanium, and is formed on the second circumferential metal film using a thick film printing technique, a plating technique or the like.

Terminal portions 24 and 25 are joined to the outer sides of the reinforcing portions 22 and 23, respectively. The terminal portions 24 and 25 have a square shape in plan view, and have a configuration in which metal films 24a and 25a are formed on the surface of crystal, ceramics, or resin, and have a configuration in which the outer dimensions including the height are larger than the reinforcing portion. Yes. The structure in which the metal film is formed on the surface also serves as a connection electrode as a whole.

When assembling the piezoelectric vibrating device, first, the crystal vibrating plate 21 and the reinforcing portions 22 and 23 are joined. That is, the brazing is performed by superimposing the metal brazing material of the reinforcing portion on the circumferential metal film of the crystal diaphragm and heating it at a predetermined temperature condition. In order to obtain an atmosphere when the quartz diaphragm is excited during brazing, airtight sealing is performed by brazing in a vacuum atmosphere when using a vacuum atmosphere, and inert gas such as nitrogen gas is used when creating an inert gas atmosphere. Performs hermetic sealing by brazing in a gas atmosphere. Also, the airtight atmosphere may be different between the front and back sides. By such bonding, it is possible to obtain a chip-type module in which the crystal diaphragm and the reinforcing portion are integrated and the excitation portion of the crystal diaphragm is hermetically sealed.

Next, the terminal portions 24 and 25 are joined to the outside of the chip-type module. The terminal portion is joined by a conductive resin joining material or a metal brazing material. Thereby, a chip-type piezoelectric vibration device can be obtained.

Such a piezoelectric vibration device is mounted so that the terminal portions 24 and 25 are in direct contact with the electrode pads formed on the mounting substrate, and are joined by a low melting point metal brazing material or the like. With such a mounting configuration, each excitation electrode of the crystal diaphragm is electrically connected to each electrode pad.

According to the present embodiment, since the terminal body is composed of the reinforcing portion and the terminal portion, the stress that may be received from the mounting substrate by the connection configuration of the reinforcing portion and the terminal portion can be relaxed, Makes the crystal diaphragm less susceptible to stress. In addition, by joining the reinforcing portion and the terminal portion with a highly flexible joining material such as a silicone-based resin joining material, or by using a metal body having a high cushioning property such as copper for the terminal portion. The buffer performance can be further improved.

  Further, as described above, in the present embodiment, since the terminal portion is configured to be larger than the quartz diaphragm or the reinforcing portion, the quartz diaphragm portion can be configured not to be in close contact with the mounting substrate. Therefore, the stress on the mounting substrate side is not directly transmitted to the piezoelectric vibration plate, and the characteristics of the piezoelectric vibration device can be stabilized. Moreover, the short circuit between terminal bodies can also be prevented. In addition, since the terminal portion has a square shape in plan view, it has no directivity when mounted on the mounting board, and mounting efficiency can be improved.

A fourth embodiment of the present invention will be described with reference to FIG. FIG. 7 is an internal cross-sectional view of the piezoelectric vibrating device according to the fourth embodiment.

  The fourth embodiment is mainly different from the above embodiments in that the configuration of the crystal diaphragm is a composite configuration of a reverse mesa and a mesa configuration and that auxiliary terminals are formed outside the terminal body. It becomes a different point.

The quartz crystal plate 31 is made of an AT cut quartz crystal vibrating element and has a square shape in plan view consisting of an X axis and a Z axis. In addition, a square-shaped thin portion is formed in each of the central regions of the front and back main surfaces of the crystal diaphragm 31, and a thick portion thicker than the thin portion is formed on the outer periphery thereof, thereby having a reverse mesa configuration. . Further, the thin portion has a middle thickness region whose middle portion is slightly thicker and thinner than the thick portion, and the thin portion itself has a mesa structure.

Excitation electrodes 311 and 312 are respectively formed in the middle thickness regions of the central portions of the thin portions on the front and back sides. Each excitation electrode has a rectangular shape or a circular shape, and is formed so as to face each other with a crystal vibrating plate interposed therebetween. In addition, extraction electrodes 311a and 312a connected to the respective excitation electrodes are formed. The extraction electrodes 311 a and 312 a have a narrow width configuration, are each drawn from the thin portion to the thick portion, and extend to the upper surface of the thick portion near the outer periphery of the main surface of the crystal diaphragm 31. In this embodiment, the circumferential metal film is not formed. However, since the extraction electrode is formed up to the thick portion, the conductive bonding can be performed by the conductive bonding material.

  The excitation electrode, the extraction electrode, and the circumferential metal film have a multilayer thin film electrode configuration, and are formed in the order of, for example, a chromium layer, a gold layer, or a silver layer in contact with a quartz crystal vibration plate. These electrodes may be formed using a vapor deposition mask having openings for forming electrodes, or may be formed using a photolithography technique.

  A terminal body is connected to the front and back main surfaces of the crystal diaphragm 31. In the present embodiment, the terminal body includes reinforcing portions 32 and 33, terminal portions 34 and 35, and auxiliary terminal portions 36 and 37, respectively. In the present embodiment, the size of the terminal portion is formed larger than the outer size of the reinforcing portion.

The reinforcement parts 32 and 33 are comprised with insulators, such as quartz or ceramics. In addition, the reinforcing portions 32 and 33 have joint surfaces 321 and 331 with the crystal diaphragm 31, and lead-out electrodes 32a and 33a extending from the joint surface to the opposite surface of the joint surface through the side surface are formed. The joint surfaces 321 and 331 of the reinforcing portion have a planar configuration, but a cavity is formed in the central portion by the thin portions of the quartz crystal plates facing each other. The lead-out electrode has a multilayer thin film electrode configuration, and is formed in the order of a chromium layer, a gold layer, or a silver layer, for example, in contact with the terminal body.

Terminal portions 34 and 35 are joined to the outer sides of the reinforcing portions 32 and 33, respectively. The terminal portion has a configuration in which metal films 34a and 35a are formed on the surface of crystal, ceramics, or resin, and has a configuration in which outer dimensions including a height dimension are larger than the reinforcing portion. The structure in which the metal film is formed on the surface also serves as a connection electrode as a whole.

  Further, in the present embodiment, auxiliary terminal portions 36 and 37 are joined to the outer side surfaces of the terminal portions 34 and 35 and on the lower side in contact with the mounting board. The auxiliary terminal portion has a configuration in which a metal plate is bent, and has an action of stabilizing the piezoelectric vibration device during mounting.

When assembling the piezoelectric vibrating device, first, the crystal vibrating plate 31 and the reinforcing portions 32 and 33 are joined. This bonding uses a conductive resin bonding material S1. A conductive resin bonding material S <b> 1 is applied in the vicinity of the outer periphery of the bonding surface of the reinforcing portion, and is superposed on the front and back surfaces of the crystal diaphragm 31. Then, by conducting heating under a predetermined temperature condition, the conductive resin bonding material is cured and conductive bonding is performed. Instead of the conductive resin bonding material, a bonding material using nano metal fine particles may be used. This is, for example, a paste in which metal fine particles disclosed in JP-A-2001-225180 are dispersed in an organic solvent, and conductive bonding can be performed. As described above, it is possible to obtain a chip-type module in which the crystal diaphragm and the reinforcing portion are integrated and the excitation portion of the crystal diaphragm is hermetically sealed.

Next, the terminal portions 34 and 35 are joined to the outside of the chip-type module. The terminal portion is bonded by a conductive resin bonding material or a bonding material using nano metal fine particles. Further, auxiliary terminal portions 36 and 37 are joined to each other on the outer side surfaces of the terminal portions 34 and 35 on the lower side in contact with the mounting substrate with a conductive resin bonding material or the like. The conductive resin bonding material may be formed on the inner side of the main surface end portion (ridge portion with the side surface). With such a configuration, the bonding material is prevented from protruding to the side surface during bonding, and a short circuit accident due to the bonding material is suppressed.

Such a piezoelectric vibration device is mounted such that the terminal portion and the auxiliary terminal portion are in direct contact with the electrode pads formed on the mounting substrate, and are joined by a low melting point metal brazing material or the like. With such a mounting configuration, each excitation electrode of the crystal diaphragm is electrically connected to each electrode pad.

According to this embodiment, the basic structure of the quartz diaphragm is an inverted mesa structure and a mesa structure is adopted in the thin wall portion, so that the excitation region in which the excitation electrode is formed in a state where energy is efficiently confined is used. Vibration can be performed. Therefore, the characteristics of the piezoelectric vibration device can be improved and stabilized.

In addition, since the terminal body is composed of the reinforcing portion, the terminal portion, and the auxiliary terminal portion, the stress that may be received from the mounting substrate can be relieved, and the influence of the stress on the crystal diaphragm is less likely to occur. In addition, each component is bonded with a highly flexible bonding material such as a silicone-based resin bonding material, or by using a metal body having a high buffering property such as copper for the auxiliary terminal portion. The performance can be further improved.

As described above, also in the present embodiment, since the terminal portion has a larger configuration than the crystal vibration plate and the reinforcing portion, the crystal vibration plate portion can be configured not to be in close contact with the mounting substrate. Therefore, the stress on the mounting substrate side is not directly transmitted to the piezoelectric vibration plate, and the characteristics of the piezoelectric vibration device can be stabilized. Moreover, the short circuit between terminal bodies can also be prevented.

A fifth embodiment of the present invention will be described with reference to FIG. FIG. 8 is an internal cross-sectional view of the piezoelectric vibrating device according to the fifth embodiment.

  The fifth embodiment differs from the above-described embodiments in that the configuration of the thin portion and the configuration of the reinforcing portion are different in the quartz diaphragm having an inverted mesa configuration.

The quartz crystal plate 41 is made of an AT-cut quartz crystal vibrating element and has a rectangular shape in plan view consisting of an X axis and a Z axis. In addition, a rectangular thin portion 41a is formed in the center region of the front and back main surfaces of the crystal diaphragm 41, and a thick portion 41b thicker than the thin portion 41a is formed on the outer periphery thereof. It has become. The thin portion 41a has an inclined surface configuration.

The inclined surface configuration is an oblique arrangement configuration extending from one main surface of the thick portion or the vicinity of the main surface to the other main surface or the vicinity of the main surface of the thick portion. The oblique arrangement configuration does not necessarily extend from the upper surface of the thick portion surface to the upper surface of the thick portion rear surface, and may be a gentle oblique arrangement configuration from the vicinity of the front surface to the vicinity of the rear surface.

Such an oblique arrangement configuration can be obtained by, for example, using a photolithography technique, a method of intermittently varying the thickness of the resist film, or a method of varying the etching rate.

Excitation electrodes 411 and 412 are respectively formed on the front and back center portions of the thin wall portion of the inclined surface configuration. Each excitation electrode has a rectangular shape or a circular shape, and is formed so as to face each other with a crystal vibrating plate interposed therebetween. In addition, an extraction electrode connected to each excitation electrode is formed. Each extraction electrode is provided on the inclined surface and is drawn from the thin portion to the thick portion, and extends to the upper surface of the thick portion near the outer periphery of the main surface of the quartz crystal plate 41. In this embodiment, the circumferential metal film is not formed. However, since the extraction electrode is formed up to the thick portion, the conductive bonding can be performed by the conductive bonding material.

  The excitation electrode and the extraction electrode have a multilayer thin film electrode configuration, and are formed in the order of, for example, a chromium layer, a gold layer, or a silver layer in contact with a quartz crystal vibration plate. These electrodes may be formed using a vapor deposition mask having openings for forming electrodes, or may be formed using a photolithography technique.

  A terminal body is connected to the front and back main surfaces of the crystal diaphragm 41. In the present embodiment, each terminal body includes a plurality of reinforcing portions 421, 422, 431, 432 and terminal portions 44, 45. In the present embodiment, the size of the terminal portion is formed larger than the outer size of the plurality of reinforcing portions.

The plurality of reinforcing portions 421, 422, 431, 432 are each made of a metal plate. One reinforcement part 421,422 is joined by a metal brazing material or conductive resin bonding material, and the other reinforcement part 431,432 is also joined by a metal brazing material or conductive resin bonding material. The joining surfaces of the reinforcing portions 421 and 431 to be joined to the quartz crystal plate have a planar configuration, but a cavity C is formed in the central portion by the thin portion of the quartz crystal plate facing each other. The plurality of reinforcing plates may be configured by forming conductive paths in an insulator such as crystal or ceramic instead of a metal plate.

Terminal portions 44 and 45 are joined to the outer sides of the reinforcing portions 422 and 432, respectively. The terminal portion may be a metal plate, or a structure in which a metal film is formed on the surface of crystal, ceramics or resin. In this embodiment, a metal plate is used. By using a metal plate, the terminal portion also serves as a connection electrode. The outer dimensions including the height dimension are larger than those of the reinforcing portion.

When assembling the piezoelectric vibration device, the integrated part of the reinforcing portions 421 and 422 is bonded to one main surface of the crystal vibrating plate, and the integrated material of the reinforcing portions 431 and 432 is bonded to the other main surface of the crystal vibrating plate. For this bonding, the conductive resin bonding material S1 is used, but the conductive resin bonding material S1 is applied in the vicinity of the outer periphery of the bonding surface of the reinforcing portion, and is superposed on the front and back surfaces of the quartz crystal plate 41. Then, by conducting heating under a predetermined temperature condition, the conductive resin bonding material is cured and conductive bonding is performed. Instead of the conductive resin bonding material, a bonding material using the above-described nano metal fine particles may be used. As described above, it is possible to obtain a chip-type module in which the crystal diaphragm and the reinforcing portion are integrated and the excitation portion of the crystal diaphragm is hermetically sealed.

Next, the terminal portions 44 and 45 are joined to the outside of the chip-type module. The terminal portions are joined by a metal brazing material, a conductive resin joining material, a sealing glass material, or the like. The terminal part has a height dimension larger than that of the reinforcing part, but in this embodiment, the terminal part is placed and joined so that a gap is formed on the mounting side to the mounting board. Yes. With such a configuration, a short circuit with the mounting substrate is prevented.

Such a piezoelectric vibration device is mounted such that the terminal portion and the auxiliary terminal portion are in direct contact with the electrode pads formed on the mounting substrate, and are joined by a low melting point metal brazing material or the like. With such a mounting configuration, each excitation electrode of the crystal diaphragm is electrically connected to each electrode pad.

According to this embodiment, the region of the thin portion is widened by the oblique arrangement configuration of the thin portion, and the characteristics of the piezoelectric vibration device can be improved by substantially expanding the vibration region. In addition, since the terminal portion has a larger configuration than the crystal diaphragm and the reinforcing portion, the crystal diaphragm portion can be configured not to be in close contact with the mounting substrate. Therefore, the stress on the mounting substrate side is not directly transmitted to the piezoelectric vibration plate, and the characteristics of the piezoelectric vibration device can be stabilized. Moreover, the short circuit between terminal bodies can also be prevented.

A sixth embodiment according to the present invention will be described with reference to FIGS. 9, 10, and 11. FIG. Also in the sixth embodiment, an AT-cut crystal diaphragm is used as the piezoelectric diaphragm. FIG. 9 is a perspective view of the piezoelectric vibration device, FIG. 10 is a plan view of a crystal diaphragm, and FIG. 11 is a cross-sectional view taken along DD in FIG.

  In the sixth embodiment, the electrode arrangement configuration formed on the quartz diaphragm is different from the other embodiments.

  The quartz vibrating plate 51 is composed of a flat AT-cut quartz vibrating element, and has a rectangular shape in plan view in which the X axis has a long side and the Z axis has a short side. Excitation electrodes 511 and 512 are respectively formed in the center regions of the front and back surfaces of the quartz crystal plate 1. Each excitation electrode has a rectangular shape and is formed so as to be opposed to each other with a quartz crystal plate interposed therebetween. However, in this embodiment, each excitation electrode 511 and 512 is oblique in plan view with respect to the rectangular shape of the crystal plate. It has a plan view inclined configuration inclined to the angle. By such a plan view tilt configuration, for example, the effect of suppressing the excitation of the unnecessary mode of the contour system depending on the frequency band or the suppression of the fundamental wave vibration of the thickness-slip vibration to promote the excitation of the overtone mode, etc. Can be obtained. It should be noted that the same effect can be obtained depending on the frequency band by arranging the opposing excitation electrodes other than the oblique arrangement in plan view so as to be biased from the central portion to the end of the crystal resonator. In particular, in the present invention in which the outer periphery of the main surface of the crystal diaphragm (piezoelectric diaphragm) is strongly restrained by the terminal body, the above suppression effect can be obtained efficiently.

In addition, extraction electrodes 511a and 521a connected to the respective excitation electrodes are formed. The extraction electrodes 511a and 512a each extend to the vicinity of the outer periphery of the main surface of the crystal vibrating plate 5.

  The excitation electrode and the extraction electrode have a multilayer thin film electrode configuration, and are formed in the order of, for example, a chromium layer, a gold layer, or a silver layer in contact with a quartz crystal vibration plate. Each layer may be formed in the order of chromium, silver, and gold. These electrodes may be formed using a vapor deposition mask having openings for forming electrodes, or may be formed using a photolithography technique.

  A terminal body is connected to the front and back main surfaces of the crystal diaphragm 11. In this embodiment, the terminal body is composed of reinforcing parts 52 and 53 and terminal parts 54 and 55, respectively, and the terminal body as a whole has a rectangular parallelepiped block shape.

The reinforcing portions 52 and 53 are made of an insulator such as quartz or ceramics. In addition, the reinforcing portions 52 and 53 have joint surfaces 521 and 531 with the crystal vibrating plate 51, and have connection electrodes 52b and 53b on the opposite surfaces of the joint surfaces. A cavity C is provided on the joint surfaces 521 and 531 of the reinforcing portion. The cavity C is a central portion of the joint surface of the terminal body, and is a concave portion corresponding to the excitation electrode forming portion of the crystal diaphragm and having a size larger than that of the excitation electrode.

  Further, grooves are formed on the side surfaces of the reinforcing portions 52 and 53, and lead-out electrodes 52a and 53a (partially not shown) are formed in the grooves. The lead-out electrodes 52a and 53a electrically connect the lead-out electrodes 511a and 512a and the connection electrodes 52b and 53b.

The lead-out electrode and the connection electrode have a multilayer thin film electrode configuration, and are formed in the order of, for example, a chromium layer, a gold layer, or a silver layer in contact with the terminal body. Alternatively, each layer may be formed in the order of chromium, silver, and gold, or another metal material may be used.

Terminal portions 54 and 55 are joined to the outer sides of the reinforcing portions 52 and 53, respectively. For example, the terminal portion may be made of a metal body such as copper or Western night, and may have a structure in which a metal plating layer or a metal brazing material is formed on the surface in order to improve connectivity. Further, the terminal portion has an outer dimension that is the same as or slightly larger than the height of the reinforcing portion. Moreover, the terminal part also has the role of a connection electrode by the structure which consists of a metal body. Note that the terminal portion may have a structure in which a conductive film is formed on part or all of the insulator. In this case, a conductive film is required which is conductively joined to the connection electrodes 52b and 53b and leads to the connection electrode.

When assembling the piezoelectric vibrating device, the crystal vibrating plate 51 and the reinforcing portions 52 and 53 are first joined in a predetermined atmosphere environment. A metal brazing material, a conductive resin bonding material, or the like is used for bonding. By such joining, it is possible to obtain a chip-type module in which the crystal diaphragm and the reinforcing portion are integrated, the excitation portion of the crystal diaphragm is hermetically sealed, and the excitation electrode is led out to the connecting electrode.

Next, terminal portions 54 and 55 are joined to the outside of the chip-type module. The terminal portion is joined by a conductive resin joining material or a metal brazing material. Thereby, a chip-type piezoelectric vibration device can be obtained.

Such a piezoelectric vibration device is mounted so that the connection electrodes 12b and 13b are in direct contact with the electrode pads P1 and P2 formed on the mounting substrate P, respectively, and are joined by a low melting point metal brazing material or the like. With such a mounting configuration, each excitation electrode of the crystal diaphragm is electrically connected to each electrode pad.

According to the present embodiment, since the terminal body is composed of the reinforcing portion and the terminal portion, the stress that may be received from the mounting substrate by the connection configuration of the reinforcing portion and the terminal portion can be relaxed, Makes the crystal diaphragm less susceptible to stress. Further, the buffering performance can be further improved by bonding the reinforcing portion and the terminal portion with a highly flexible bonding material, or by using a metal body having a high buffering property such as copper for the terminal portion. it can.

In addition, the plan view tilt configuration of the excitation electrode may suppress the excitation of the unnecessary mode of the outline system depending on the frequency band, or suppress the fundamental wave vibration of the thickness shear vibration to promote the excitation of the overtone mode, etc. The effect of can be obtained.

  A seventh embodiment according to the present invention will be described with reference to the drawings. Also in the present embodiment, an AT-cut crystal diaphragm that operates by thickness shear vibration is used as the piezoelectric diaphragm.

  FIG. 12 is a perspective view of the piezoelectric vibration device according to the seventh embodiment, and FIG. 13 is a cross-sectional view taken along line EE of FIG.

  The quartz crystal plate 61 is composed of a flat AT-cut quartz crystal resonator element, and has a rectangular shape in plan view in which the X-axis has a long side and the Z-axis has a short side on its main surface. Terminal bodies 62 and 63 are connected to the front and back main surfaces of the crystal diaphragm 61. The terminal bodies 62 and 63 have a rectangular parallelepiped block shape and are made of an insulator such as crystal or ceramics.

The terminal bodies 62 and 63 have a surface (bonding surface) facing the crystal diaphragm 61, and have formation surfaces of connection electrodes 62b and 63b on the surface opposite to the bonding surface. Excitation electrodes 621 and 631 are formed in the central region of the surface facing the quartz crystal plate, respectively. Each excitation electrode has a rectangular shape, and is formed so as to face each other with a crystal diaphragm. In addition, an extraction electrode connected to each excitation electrode is formed, and the extraction electrode has a narrow width configuration (not shown), and extends to the vicinity of the outer periphery of the main surface of the crystal diaphragm 1. The excitation electrode may have a rectangular cutout shape, a circular shape, or an oval shape.

Further, a groove is formed on the side surface of each terminal body 62, 63, and lead-out electrodes 62a, 63a (partially not shown) are formed in the groove. The lead electrodes and the connection electrodes 62b and 63b are electrically connected by the lead-out electrodes 62a and 63a. Note that a through hole may be provided in the terminal body, and a lead-out electrode may be provided in the through hole.

  The excitation electrode, the extraction electrode, and the connection electrode have a multilayer thin film electrode configuration, and are formed in the order of a chromium layer, a gold layer, or a silver layer, for example, in contact with a crystal diaphragm or a terminal body. These electrodes may be formed using a vapor deposition mask having openings for forming electrodes, or may be formed using a photolithography technique.

The crystal diaphragm 61 and the terminal bodies 62 and 63 are joined using a sealing glass material. Specifically, sealing glass is formed in the vicinity of the outer periphery of the surface of the terminal body facing the crystal diaphragm, the crystal diaphragm and each terminal body are overlaid in an atmosphere of inert gas, etc., and heated at a predetermined temperature condition By performing the above, airtight sealing with a sealing glass material is performed. By such bonding, it is possible to obtain a chip-type piezoelectric vibration device having a configuration in which an excitation electric field is applied to the crystal diaphragm by an air gap method. The sealing glass forms a gap between the excitation region of the quartz crystal plate and the excitation electrode of the terminal body, so that an excitation space can be obtained. The gap can be adjusted depending on the thickness of the sealing glass material, and the gap can be adjusted by forming a concave or convex portion on the quartz diaphragm or the terminal body as necessary. . The hermetic sealing may use a metal brazing material or a resin bonding material in addition to the sealing glass material.

Such a piezoelectric vibration device is mounted so that the connection electrodes 62b and 63b are in direct contact with the electrode pads formed on the mounting substrate, and are joined by a low melting point metal brazing material such as lead-free solder or the like S5. With such a mounting configuration, each excitation electrode of the crystal diaphragm is electrically connected to each electrode pad.

In the above-described embodiment, the quartz diaphragm (piezoelectric diaphragm) and the terminal body are joined using a metal brazing material, and brazing is performed by overall heating. However, the joining is performed using an energy beam such as a laser beam. The part may be heated locally.

  With the above configuration, it is possible to make a simple configuration without using a ceramic package as in the past, and when the crystal diaphragm is mounted, the configuration is mounted almost perpendicular to the mounting substrate. An extremely small chip-type piezoelectric vibration device can be obtained by the integrated configuration.

  The present invention is not limited to the above-described embodiment, and for example, the crystal resonator element and the excitation electrode may be circular or oval, and various modifications can be applied. The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  Applicable for mass production of crystal units.

It is a disassembled perspective view which shows 1st Embodiment by this invention. It is AA sectional drawing at the time of assembling FIG. It is a perspective view which shows 2nd Embodiment by this invention. It is BB sectional drawing of FIG. It is a perspective view which shows 3rd Embodiment by this invention. It is CC sectional drawing of FIG. It is sectional drawing which shows 4th Embodiment by this invention. It is sectional drawing which shows 5th Embodiment by this invention. It is a perspective view which shows 6th Embodiment by this invention. It is a top view of the crystal diaphragm of 6th Embodiment by this invention. It is CC sectional drawing of FIG. It is a perspective view which shows 7th Embodiment by this invention. It is DD sectional drawing of FIG.

11, 21, 31, 41, 51, 61 Quartz diaphragm (piezoelectric diaphragm)
111, 112, 211, 212, 311, 312, 311, 412, 511, 512, 621, 631 Excitation electrodes 12, 13, 62, 63 Terminal bodies 14, 15, 22, 23, 32, 33, 421, 422 431, 432, 52, 53 Reinforcement part 16, 17, 24, 25, 44, 45, 54, 55 Terminal part

Claims (8)

A pair of excitation electrodes are formed on the front and back main surfaces, and a rectangular piezoelectric diaphragm in which an extraction electrode connected to the excitation electrode is drawn to the vicinity of the outer periphery, and connected to the front and back outer periphery of the piezoelectric vibration plate, the front and back main surfaces A piezoelectric vibration device having a pair of rectangular parallelepiped block-like terminal bodies having the same or larger joint surface,
Each terminal body has a wiring pattern connected to only one or the other of the lead electrodes, and the electrode is led out on the opposite surface of the joint surface connected to the piezoelectric diaphragm, and each terminal body is connected to the mounting substrate. Directly contacted and electrically and mechanically connected by a conductive bonding material, the terminal body is composed of a reinforcing portion and a terminal portion, and the reinforcing portion is connected to the vicinity of the front and back outer periphery of the piezoelectric diaphragm, and is connected to the reinforcing portion. A piezoelectric vibration device characterized in that the excitation electrode is led out to the outside by a terminal portion . A piezoelectric vibration device having a rectangular piezoelectric diaphragm and a pair of rectangular parallelepiped block-like terminal bodies connected to the vicinity of the front and back outer peripheries of the piezoelectric diaphragm and having a joint surface that is the same as or larger than the front and back main surfaces,
Each terminal body has an excitation electrode on a surface facing the piezoelectric diaphragm, and an extraction electrode that draws the excitation electrode to the vicinity of the outer periphery of each terminal body, and each terminal body has a mounting substrate. The terminal body is composed of a reinforcing part and a terminal part, and the reinforcing part is connected to the vicinity of the front and back outer periphery of the piezoelectric diaphragm, and is connected to the reinforcing part. A piezoelectric vibration device characterized in that the excitation electrode is led out to the outside by a terminal portion . 3. The piezoelectric vibration according to claim 1, wherein the terminal body is connected to the vicinity of the front and back outer peripheries of the piezoelectric diaphragm, and a cavity is formed at a position facing the central portion of the piezoelectric diaphragm. device. The piezoelectric diaphragm has a configuration in which the vicinity of the outer periphery connected to the terminal body has a thick portion, and the central portion has a thin portion thinner than the thick portion, and an excitation electrode is formed on the thin portion, or 4. The piezoelectric vibration device according to claim 1, wherein an excitation electrode is formed in a region corresponding to the thin portion of the terminal body . 5. The piezoelectric vibration device according to claim 4, wherein the thin portion has an oblique arrangement configuration extending from one main surface or the vicinity of the main surface of the thick portion to the other main surface or the vicinity of the main surface of the thick portion . 6. The piezoelectric vibration device according to claim 1, wherein at least one of the piezoelectric vibration plate and the terminal body or the reinforcing portion and the terminal portion is bonded with a flexible resin bonding material . The said reinforcement part consists of an insulator with which the wiring pattern was formed, and the said terminal part is the structure which formed the metal film on the surface of the metal plate or the insulation board, The Claim 1 thru | or 6 characterized by the above-mentioned. The piezoelectric vibration device as described . 8. The height dimension of each terminal body is larger than the height dimension of the piezoelectric diaphragm, and a gap is formed between the piezoelectric diaphragm and the mounting board when the mounting board is mounted. The piezoelectric vibration device as described .

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